ABSTRACT
OBJECTIVE@#This test was designed to evaluate the effect of lower-limb dominance and non-dominance shuttle runs under load carriage during different exercise load at the same exercise intensity on the balance responses.@*METHODS@#Ten healthy young males were joined in this experiment, they were (20.80±2.04) years old and (173.99±2.87) cm tall. In a randomized cross-over design, they performed four times shuttle runs under unilateral load carriage:20 m×5 at dominant side, 20 m×5 at non-dominant side, 20 m×10 at dominant side, 20 m×10 at non-dominant side respectively. Balance abilities were evaluated immediately and 20 minute post-exercise respectively, and R-R interval was recorded.@*RESULTS@#The HR, EPOC and TRIMP for all exercise load were increased significantly after shuttle runs compared to rest (0.05), which showed symmetrical change. In addition, during 20 minute recovery, the balance ability for all exercise load was returned to the rest value (>0.05).@*CONCLUSIONS@#The shuttle runs could impair the trunk control ability immediately post-exercise, the magnitude of mediolateral movement was increased as the exercise load increased. The changes of balance responses were similar between the dominant and the non-dominant side, the dominant and the non-dominant side might show cross-effects.
Subject(s)
Adolescent , Humans , Male , Young Adult , Exercise , Exercise Test , Lower Extremity , Movement , RunningABSTRACT
BACKGROUND: Eccentric exercise displays many advantages over concentric and isometric contractions, and it has been applied in exercise training and rehabilitation. The existing researches focus on the underlying mechanisms at molecular and neural levels, and the specific adaptation after eccentric exercise may be related to the adaptive signaling pathway. OBJECTIVE: To review the unique physiological characteristics and mechanisms of eccentric exercise, thereby providing reference for in-depth understanding of eccentric exercise. METHODS: The relevant articles were searched in PubMed (1990-2017) and CNKI (2010-2017) with the keywords of "eccentric exercise, negative muscle work, eccentric exercise training, downhill run, concentric exercise, positive muscle work, concentric exercise training, and uphill running" in English and Chinese, respectively. Ultimately, the articles eligible for physiological characteristics, acute response and adaptive mechanism were enrolled. RESULTS AND CONCLUSION: Totally 98 articles were retrieved, and 54 pertinent papers were enrolled for analysis based on the inclusion and exclusion criteria. The mechanical, molecular and neural mechanisms of eccentric contractions differ from those of concentric and isometric contractions. Special metabolic and cardiorespiratory responses after eccentric exercise reflect the advantages in making programs of exercise training and rehabilitation. Particularly, compared with concentric exercise, fewer motor units are recruited during eccentric exercise and exert muscle a greater stimulation, which involves the process of exercise-induced muscle damage and the activation of satellite cells. The content of satellite cells after eccentric exercise is higher than that of concentric exercise, suggesting that satellite cells may play an important role in the muscle damage reconstruction caused by eccentric exercise. In conclusion, eccentric exercise is of great significance for exercise training and rehabilitation, while further study on the adaptive mechanism of eccentric exercise is necessary.